160 degree thermostat, yes. Larger heat exchanger, no

Thermostat:

Replacing the factory 160 degree thermostat went relatively smoothly, once I drained the coolant and found a Torx E10 socket (not Torx bit, but a Torx socket) to remove the Torx bolts.

Old thermostat housing removed:



(Somewhat surprising to see varnish inside a relatively new engine)

New thermostat installed (Torx bolt heads visible):



Another surprise was the absence of a coolant drain plug/bolt/whatever.

The drain plug is indicated by yellow arrow (photo from the 'net):



Couldn't find one on my engine:



So, I did what the Porsche service manual says - disconnected the hoses, whereupon I had coolant in my hair, ears, and mouth. Tastes sweet. I can see why dogs and cats like it.

Pedro's bleeding instructions are excellent. I followed them carefully.

[pedrosgarage.com]

Heat Exchanger:

The 'S' heat exchanger was a no-go. It's 1 3/4" taller than the non-S unit and there simply wasn't ANY room for it. I couldn't find a way to reposition the intake hose and related parts to create space. I certainly didn't want to break anything. My stock heat exchanger:

Top view:



A closer top view:



View from the left side:



As far as I can tell, the photos I've seen on the 'net (below) depict a pre-987 motor:





Kudos to the seller for allowing me to return it a LONG time after I bought it. (It can take me YEARS to get around to these jobs)

I hope this is informative and helpful to anyone contemplating these modifications to their 987.